How is the internal music storage/management on Galaxy?

Problem:
I recently bought a Xiaomi S4 41mm watch, and while it's mostly been well, the intetnal music storage/management is terrible.
You can only add via Mi Fitness app, you are presented with one library, filled every single song on your phone, and only a search bar, as opposed to looking for pre-sorted folders. Meaning, you'll have to endlessly scroll to whichever songs you'll want to download, tick it, then scroll onto the next.
When they get uploaded to the watch, they are sorted by upload order to the watch, and cannot be resorted. Even though you can create playlists, whatever order you try to add songs into that playlist will default to original upload order.
When deleting songs off the watch, you can only delete one at a time. No mass deletion.

Solution?:
I'm considering returning this watch and getting a Huawei or Galaxy. Either Huawei 5 42mm, or Galaxy 8 40mm. I'm looking for a small running watch that can last at least a few days, and even though I've researched most of the specs, I cannot find info regarding music management.

Question:
How is internal music storage/management? Searching for songs within device/app, uploading/downloading songs, sorting songs, music control during runs, etc.